Water Contents of Early Cretaceous Mafic Dikes in the Jiaodong Peninsula, Eastern North China Craton: Insights into an Enriched Lithospheric Mantle Source Metasomatized by Paleo–Pacific Plate Subduction–Related Fluids
Water Contents of Early Cretaceous Mafic Dikes in the Jiaodong Peninsula, Eastern North China Craton: Insights into an Enriched Lithospheric Mantle Source Metasomatized by Paleo–Pacific Plate Subduction–Related Fluids
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华北克拉通东部胶东半岛早白垩世基性岩脉含水量：古太平洋板块俯冲交代富集岩石圈地幔源区洞察——相关流体
DOI：
10.1086/702648
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发表时间：
2019-03
影响因子：
1.8
通讯作者：
Lihua Zhao
中科院分区：
文献类型：
--
作者：
Yayun Liang;Jun Deng;Xuefei Liu;Qingfei Wang;Yao Ma;Tianxiang Gao;Lihua Zhao
胶东半岛早白垩世岩石圈地幔为古老富集型地幔，分布着广泛的镁铁质岩墙群。然而，岩石圈地幔的富集剂和过程仍然存在争议。利用单斜辉石斑晶的H2O含量和H2O分配系数DH2Ocpx/熔体，恢复了胶东半岛早白垩世基性岩脉原始岩浆的H2O含量。我们还提供了这些基性岩脉中CPx斑晶的全岩地球化学数据和原位主元素和微量元素含量。这些岩脉具有低SiO_2含量、高镁含量、富大离子亲石元素和轻稀土元素、亏损高场强元素、高(87sr/86sr)i比值和低εNd(T)值的特征。这些地球化学特征暗示了富集型次大陆岩石圈地幔的起源。计算的原始岩浆H2O含量为1.38~4.45wt%，H2O/Ce比值为237~322，表明其地幔源区受到洋板俯冲相关流体的交代作用。此外，H2O/Ce和不相容元素的协变表明，胶东基性岩脉的地幔源区增加了一种脱水的海相沉积物组分。结合中国克拉通东南部早白垩世玄武岩的H2O含量，岩石圈地幔通过与古太平洋板块俯冲有关的流体交代。
The Early Cretaceous lithospheric mantle beneath the Jiaodong Peninsula has been recognized as ancient and enriched mantle with widespread mafic dike swarms. However, the enriching agent and the process of the lithospheric mantle remain under debate. In this study, we recovered the H2O contents of the primitive magmas of Early Cretaceous mafic dikes in the Jiaodong Peninsula by using the H2O contents of clinopyroxene (Cpx) phenocrysts and H2O partition coefficients DH2Ocpx/melt. We also present whole-rock geochemical data and in situ major- and trace-element contents for Cpx phenocrysts from these mafic dikes. These dikes are characterized by low SiO2 contents, high MgO contents, enrichment of large-ion lithophile elements and light rare earth elements, depletion of high-field-strength elements, high (87Sr/86Sr)i ratios, and low εNd(t) values. These geochemical features imply an origin of enriched subcontinental lithospheric mantle. The calculated H2O contents of the primitive magmas range from 1.38 to 4.45 wt%, with associated H2O/Ce ratios varying from 237 to 322, suggesting that their mantle source was metasomatized by oceanic slab subduction–related fluids. In addition, covariations between H2O/Ce and incompatible elements indicate the addition of a dehydrated marine sediment component in the mantle source of the Jiaodong mafic dikes. In combination with the H2O contents of Early Cretaceous basaltic rocks in the southeastern North China Craton, the lithospheric mantle was metasomatized through fluids related to paleo–Pacific plate subduction.
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DOI：
--
发表时间：
2007
期刊：
--
影响因子：
--
作者：
D. IrrrNcrn;Gnoncr R. RossunN
通讯作者：
D. IrrrNcrn;Gnoncr R. RossunN
影响因子：
3.7
作者：
Y. Tatsumi;T. Hanyu
通讯作者：
Y. Tatsumi;T. Hanyu
华北克拉通东南部岩石圈地幔与俯冲相关的交代作用：苏鲁造山带北部镁铁质岩脉到中间岩脉的证据
影响因子：
2.9
作者：
M. Santosh;Fang-Fang Hu;Kui-Feng Yang;Zhaochu Hu
通讯作者：
Zhaochu Hu
影响因子：
3.9
作者：
Liu, Jia;Xia, Qun-Ke;Feng, Min
通讯作者：
Feng, Min
青藏高原拉萨地体狮泉河-云珠-纳木措蛇绿岩带云珠蛇绿岩成因的年代学和地球化学约束
影响因子：
3.5
作者：
Zeng Y.C.;Xu J.F.;Chen J.L.;Wang B.D.;Kang Z.Q.;Huang F.
通讯作者：
Huang F.